Pattern Abstract Grammar
Structured Instructions for AI Systems
BNF Grammar
PAG is defined by a formal Context-Free Grammar (CFG) expressed in BNF notation. The complete grammar is organized into five rule categories.
Planning Rulesα
Grammar for document structure, phases, validation gates, and meta information.
BNF Grammar# Instruction <instruction> ::= <frontmatter> <optional_meta_block> <optional_document_declaration> <body> <frontmatter> ::= "---" <yaml_content> "---" <optional_meta_block> ::= <meta_block> | ε <optional_document_declaration> ::= <document_declaration> | ε <document_declaration> ::= "THIS" <document_type> <document_verb> <description> <document_type> ::= "AGENT" | "COMMAND" | "TASK" | "WORKFLOW" | "INSTRUCTION" | "TEST" | "TEMPLATE" | "POLICY" | "PROTOCOL" | "CHECKLIST" | "PROMPT" <document_verb> ::= "IS" | "ENFORCES" | "EXECUTES" | "HAS" | "PERFORMS" | "PROVIDES" | "IMPLEMENTS" | "DEFINES" | "MANAGES" | "COORDINATES" <description> ::= <text> <body> ::= <phase>+ # Meta Block <meta_block> ::= "%%" "META" "%%" ":" <meta_field>+ <meta_field> ::= "intent" ":" <string> | "context" ":" <string> | "objective" ":" <string> | "criteria" ":" <string> | "priority" ":" ("high" | "medium" | "low") | "recursion_limit" ":" <number> # Phase <phase> ::= <optional_phase_meta_block> <optional_context_cue> <phase_header> <phase_body> <phase_header> ::= "#" "PHASE" <phase_number> ":" <phase_title> | "#" <phase_type> ":" <phase_title> | "#" <semantic_phase_name> ":" <phase_title> <phase_number> ::= <digit>+ ("." <digit>+)? <phase_type> ::= "SETUP" | "ACTION" | "ANALYZE" | "CLEANUP" <semantic_phase_name> ::= "FIND" | "INVESTIGATE" | "EXTRACT" | "ANALYZE" | "FINALIZE" <phase_title> ::= <text> <optional_phase_meta_block> ::= <meta_block> | ε <optional_context_cue> ::= <context_cue> | ε # Phase Body <phase_body> ::= (<directive> | <validation_gate>)+ # Meta Tag <meta_tag> ::= "@" ("purpose" | "context" | "focus" | "expected_output") ":" <string> # Macro <macro> ::= "USE" "TEMPLATE" <template_name> <template_name> ::= <identifier> # Context Cue <context_cue> ::= "CUE" ("color" | "sound" | "scent" | "signal") ":" <string> # Validation Gate <validation_gate> ::= <gate_marker> <check_item>+ <gate_marker> ::= "**" "Validation" "Gate" "**" ":" | "##" "Validation" "Gate" <check_item> ::= <check_marker> <check_condition> <optional_check_evidence> <optional_failure_action> <optional_check_evidence> ::= <check_evidence> | ε <optional_failure_action> ::= <failure_action> | ε <check_marker> ::= "✅" | "ASSERT" | "REQUIRE" | "ANALYZE" | "[high]" | "[medium]" | "[low]" <check_condition> ::= <boolean_expr> <check_evidence> ::= "(" "ANALYZE" <verification_expr> ")" <failure_action> ::= "IF" "FAIL" ":" <directive>+ # Rule <rule_declaration> ::= "RULE" <rule_name> ":" <rule_body> <rule_name> ::= <identifier> <rule_body> ::= <when_clause>* <directive>+ <optional_validation_gate> <when_clause> ::= "WHEN" <condition> ":" <directive>+ <optional_validation_gate> ::= <validation_gate> | ε # Step <step_statement> ::= "STEP" <step_identifier> ":" <directive>+ <step_identifier> ::= <number> | <identifier>
Statement Rulesβ
Grammar for directives, actions, control flow, and declarations.
BNF Grammar# Directive <directive> ::= <optional_task_marker> <optional_meta_tag> <optional_context_cue> <directive_body> <directive_body> ::= <action_expr> | <control_flow> | <declaration_statement> | <transform_statement> | <discovery_statement> | <iteration_statement> | <function_declaration> | <announcement_statement> | <state_machine_declaration> | <dag_declaration> | <priority_queue_declaration> | <priority_queue_operation> | <flowchart_declaration> | <mermaid_declaration> | <ascii_flowchart_block> | <macro> <optional_task_marker> ::= <task_marker> | ε <task_marker> ::= "[" <task_state> "]" <task_state> ::= " " | "x" | "!" | ">" | "~" <optional_meta_tag> ::= <meta_tag> | ε # Action Expr <action_expr> ::= <action_verb> <modifier>* <action_target> <optional_action_args> <action_verb> ::= "EXECUTE" | "READ" | "WRITE" | "REMOVE" | "ANALYZE" | "CREATE" | "FIND" | "REPORT" | "COLLECT" | "EXTRACT" | "LINK" | "DETERMINE" | "INVESTIGATE" | "FILTER" | "COMPARE" | "MARK" | "SORT" | "RANK" | "ORDER" | "INSERT" | "APPEND" | "ADD" | "MOVE" | "COPY" | "BACKUP" | "RESTORE" | "GLOB" | "GREP" | "SET" | "ITERATE" | "ATTEMPT" | "FAIL" | "EXIT" | "RETURN" | "WAIT" | "SEND" | "REDUCE" | "PROPAGATE" | "FINALIZE" | "EVIDENCE" <modifier> ::= "MUST" | "NEVER" | "ALWAYS" | "REQUIRED" | "MANDATORY" <action_target> ::= <tool_name> | <path> | <variable_name> <tool_name> ::= "SYSTEM" | "USER" | "SERVICE" <optional_action_args> ::= <parenthesized_args> | <bare_args> | ε <parenthesized_args> ::= "(" <arg_list> ")" <bare_args> ::= <arg_list> <arg_list> ::= <arg> ("," <arg>)* <arg> ::= <identifier> | <literal> | <expression> # Control Flow <control_flow> ::= <if_statement> | <for_loop> | <while_loop> | <try_catch> | <goto_statement> | <label_declaration> | <flow_marker> <if_statement> ::= "IF" <condition> ":" <directive>+ ("ELSE" "IF" <condition> ":" <directive>+)* <optional_else_clause> <optional_else_clause> ::= ("ELSE" ":" <directive>+) | ε <for_loop> ::= "FOR" "EACH" <iterator> "IN" <collection> ":" <directive>+ <while_loop> ::= "WHILE" <condition> ":" <directive>+ <try_catch> ::= "TRY" ":" <directive>+ "CATCH" <optional_exception_var> ":" <directive>+ <optional_exception_var> ::= <exception_var> | ε <exception_var> ::= <identifier> <goto_statement> ::= "GOTO" <label_identifier> <label_declaration> ::= <label_identifier> ":" <label_identifier> ::= <identifier> <flow_marker> ::= "START" <optional_label> | "LOOP" <optional_backto> | "END" | "STOP" <optional_label> ::= <identifier> | ε <optional_backto> ::= ("BACKTO" <identifier>) | ε # Declaration Statement <declaration_statement> ::= "SET" <variable_name> "=" <expression> | "DECLARE" <variable_name> ":" <type_annotation> <type_annotation> ::= "string" | "number" | "boolean" | "array" | "object" | "file" | "context" # Transform Statement <transform_statement> ::= <backup_directive> <edit_directive> <optional_analyze_directive> <backup_directive> ::= "BACKUP" <path> "TO" <backup_location> | "COPY" <path> "TO" <backup_location> <edit_directive> ::= "WRITE" <path> <write_spec> | "EXECUTE" <edit_command> <path> <edit_command> ::= <identifier> <analyze_directive> ::= "ANALYZE" <verification_condition> <optional_analyze_directive> ::= <analyze_directive> | ε <backup_location> ::= <path> <edit_spec> ::= "WITH" <expression> | "USING" <template_name> | <string> <write_spec> ::= "CONTENT" <string> | "FROM" <source_file> | "INTO" <destination> | <string> <source_file> ::= <path> <destination> ::= <path> <verification_condition> ::= <condition> # Discovery Statement <discovery_statement> ::= <discovery_action> <optional_verification_check> <discovery_action> ::= "GLOB" <pattern> <optional_scope> | "GREP" <search_pattern> <optional_search_scope> | "FIND" <search_term> "IN" <search_location> <verification_check> ::= "IF" "exists" ":" <directive>+ | "ANALYZE" <expression> <comparison_op> <expression> <optional_verification_check> ::= <verification_check> | ε <optional_scope> ::= "IN" <scope> | ε <optional_search_scope> ::= "IN" <search_scope> | ε <scope> ::= <path> <search_scope> ::= <path> <search_location> ::= <path> <search_pattern> ::= <string> | <regex_literal> <search_term> ::= <string> <collection_var> ::= <variable_name>
Expression Rulesγ
Grammar for expressions, operators, literals, and lexical elements.
BNF Grammar# Expressions <expression> ::= <pipeline_expr> <pipeline_expr> ::= <logical_or_expr> ("|>" <logical_or_expr>)* <logical_or_expr> ::= <logical_and_expr> ("OR" <logical_and_expr>)* <logical_and_expr> ::= <equality_expr> ("AND" <equality_expr>)* <equality_expr> ::= <relational_expr> (("===" | "!==") <relational_expr>)* <relational_expr> ::= <additive_expr> (("<" | ">" | "<=" | ">=") <additive_expr>)* | <additive_expr> "MATCHES" <pattern> | <additive_expr> "FOR" <expression> | <additive_expr> "BETWEEN" <expression> <additive_expr> ::= <multiplicative_expr> (("+" | "-") <multiplicative_expr>)* <multiplicative_expr> ::= <unary_expr> (("*" | "/" | "%") <unary_expr>)* <unary_expr> ::= ("!" | "NOT" | "-" | "+") <postfix_expr> | <postfix_expr> <postfix_expr> ::= <primary_expr> <postfix_op>* <postfix_op> ::= "[" <expression> "]" | "." <identifier> | "(" <optional_arg_list> ")" <primary_expr> ::= <array_literal> | <object_literal> | <literal> | <identifier> | "(" <expression> ")" <array_literal> ::= "[" <optional_expression_list> "]" <object_literal> ::= "{" <optional_key_value_pairs> "}" <expression_list> ::= <expression> ("," <expression>)* <optional_expression_list> ::= <expression_list> | ε <key_value_pair> ::= <object_key> ":" <expression> <object_key> ::= <identifier> | <string> | <number> <key_value_pairs> ::= <key_value_pair> ("," <key_value_pair>)* <optional_key_value_pairs> ::= <key_value_pairs> | ε <function_call> ::= <function_name> "(" <optional_arg_list> ")" <optional_arg_list> ::= <arg_list> | ε <condition> ::= <expression> <boolean_expr> ::= <logical_or_expr> <verification_expr> ::= <expression> <term> ::= <multiplicative_expr> <factor> ::= <primary_expr> <pattern> ::= <string> | <regex_literal> <regex_literal> ::= "/" <regex_pattern> "/" <optional_regex_flags> <optional_regex_flags> ::= <regex_flags> | ε <regex_pattern> ::= <any_regex_character>+ <regex_flags> ::= <letter>+ <comparison_op> ::= "===" | "!==" | "<" | ">" | "<=" | ">=" # Lexical <identifier> ::= <letter> (<letter> | <digit> | "_" | "-")* <variable_name> ::= <identifier> <function_name> ::= <identifier> <node_name> ::= <identifier> <path> ::= <directory_path> | <file_path> <directory_path> ::= <path_segment> ("/" <path_segment>)* "/" <file_path> ::= <path_segment> ("/" <path_segment>)* <optional_file_extension> <path_segment> ::= <identifier> <optional_file_extension> ::= ("." <identifier>) | ε <literal> ::= <number> | <string> | <boolean> <number> ::= <digit>+ <optional_decimal> <optional_decimal> ::= ("." <digit>+) | ε <string> ::= '"' <char>* '"' | "'" <char>* "'" <boolean> ::= "true" | "false" <digit> ::= "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" <letter> ::= "a".."z" | "A".."Z" <char> ::= <any_character> <text> ::= <char>+ <yaml_content> ::= <text> <any_character> ::= <letter> | <digit> | <whitespace> | <symbol> <symbol> ::= "_" | "-" | "." | "," | ":" | ";" | "!" | "?" | "@" | "#" | "$" | "%" | "^" | "&" | "*" | "(" | ")" | "[" | "]" | "{" | "}" | "<" | ">" | "/" | "\" | "|" | "=" | "+" | "`" | "~" <any_regex_character> ::= <letter> | <digit> | <symbol> <whitespace> ::= " " | " " | " " | " " # Iteration Statement <iteration_statement> ::= <loop_header> <loop_body> <loop_header> ::= "FOR" "EACH" <iterator> "IN" <collection> <loop_body> ::= ":" <directive>+ <optional_accumulation> <optional_recursion_limit> <accumulation_statement> ::= "APPEND" <value> "TO" <accumulator> | "CREATE" <structure> "FROM" <iterator> | "EXTRACT" <components> "INTO" <structure> | "WRITE" <data> "INTO" <storage> | "COLLECT" <items> "INTO" <collection> | "SET" <state_var> "=" <state_expr> <recursion_limit> ::= "MAX_DEPTH" "=" <number> <optional_accumulation> ::= <accumulation_statement> | ε <optional_recursion_limit> ::= <recursion_limit> | ε <iterator> ::= <variable_name> <collection> ::= <variable_name> | <expression> <value> ::= <expression> <accumulator> ::= <variable_name> <structure> ::= <variable_name> <components> ::= <expression> <data> ::= <expression> <items> ::= <expression> <storage> ::= <variable_name> <state_var> ::= <variable_name> <state_expr> ::= <expression> # Function Declaration <function_declaration> ::= "FUNCTION" <function_name> "(" <optional_param_list> ")" ":" <directive>+ <optional_param_list> ::= <param_list> | ε <param_list> ::= <parameter> ("," <parameter>)* <parameter> ::= <variable_name> # Announcement Statement <announcement_statement> ::= "REPORT" <message> <message> ::= <string> | <expression>
Coordination Rulesδ
Grammar for async operations, state machines, DAGs, and tool invocations.
BNF Grammar# Await <await_statement> ::= "AWAIT" <awaitable_expression> <optional_result_binding> <awaitable_expression> ::= <identifier> | <string> | <tool_invocation> <optional_result_binding> ::= "INTO" <identifier> | ε # Parallel <parallel_block> ::= "PARALLEL" ":" <directive>+ "END" # State Machine <state_machine_declaration> ::= "STATE_MACHINE" <machine_name> ":" <state_definition>+ <transition_definition>+ <state_definition> ::= "STATE" <state_name> <optional_state_type> <optional_entry_actions> <optional_exit_actions> <transition_definition> ::= "TRANSITION" "FROM" <state_name> "TO" <state_name> "ON" <event_name> <optional_guard> <optional_transition_actions> <optional_state_type> ::= ":" <state_type> | ε <optional_entry_actions> ::= "ENTRY" ":" <directive>+ | ε <optional_exit_actions> ::= "EXIT" ":" <directive>+ | ε <optional_guard> ::= "GUARD" ":" <condition> | ε <optional_transition_actions> ::= ":" <directive>+ | ε <machine_name> ::= <variable_name> <state_name> ::= <variable_name> <state_type> ::= <identifier> <event_name> ::= <variable_name> # DAG <dag_declaration> ::= "DAG" <dag_name> ":" <dag_item>+ <optional_validation_gate> <dag_item> ::= <node_definition> | <parallel_group> <node_definition> ::= "NODE" <node_name> <optional_node_type> <optional_depends_on> <optional_after> <optional_before> ":" <directive>+ <parallel_group> ::= "PARALLEL_GROUP" ":" <node_name_list> <dependency_list> ::= <node_name> ("," <node_name>)* <dependent_list> ::= <node_name> ("," <node_name>)* <node_name_list> ::= <node_name> ("," <node_name>)* <optional_validation_gate> ::= <validation_gate> | ε <optional_node_type> ::= ":" <node_type> | ε <optional_depends_on> ::= "DEPENDS_ON" <dependency_list> | ε <optional_after> ::= "AFTER" <dependency_list> | ε <optional_before> ::= "BEFORE" <dependent_list> | ε <dag_name> ::= <variable_name> <node_type> ::= <identifier> # Priority Queue <priority_queue_declaration> ::= "PRIORITY_QUEUE" <queue_name> <optional_comparison> ":" <priority_queue_operation> ::= <enqueue_statement> | <dequeue_statement> | <peek_statement> | <heapify_statement> <enqueue_statement> ::= "ENQUEUE" <value> "TO" <queue_name> <optional_priority> <dequeue_statement> ::= "DEQUEUE" "FROM" <queue_name> <optional_target> <peek_statement> ::= "PEEK" <queue_name> <optional_target> <heapify_statement> ::= "HEAPIFY" <queue_name> <comparison_function> ::= <function_name> | "(" <optional_param_list> ")" "→" <expression> <optional_comparison> ::= "COMPARE_BY" <comparison_function> | ε <optional_priority> ::= "PRIORITY" "=" <priority_value> | ε <optional_target> ::= "TO" <target_variable> | ε <queue_name> ::= <variable_name> <priority_value> ::= <number> | <expression> <target_variable> ::= <variable_name> # Cross Reference <cross_reference_statement> ::= <collect_from_statement> | <find_in_statement> | <reference_statement> | <link_statement> <collect_from_statement> ::= "FROM" <file_path_pattern> "COLLECT" <selector> "TO" <target_variable> <find_in_statement> ::= "FROM" <file_path_pattern> "FIND" <search_term> "TO" <target_variable> <reference_statement> ::= "REFERENCE" <file_path_pattern> <optional_alias> <link_statement> ::= "LINK" <source_expression> "TO" <file_reference> <file_path_pattern> ::= <string> | <glob_pattern> <glob_pattern> ::= <string> <file_reference> ::= <string> <optional_anchor> <optional_anchor> ::= "#" <identifier> | ε <selector> ::= <expression> | "*" <search_term> ::= <string> | <regex_literal> <target_variable> ::= <variable_name> <source_expression> ::= <expression> <alias> ::= <identifier> <optional_alias> ::= "AS" <alias> | ε # Tool Invocation <tool_invocation> ::= <tool_verb> <tool_target> <optional_tool_param_clause> <optional_tool_result_clause> <tool_verb> ::= "READ" | "WRITE" | "EDIT" | "GLOB" | "GREP" | "BASH" | "BASH_OUTPUT" | "KILL_SHELL" | "TASK" | "TODO_WRITE" | "ASK_USER" | "WEB_FETCH" | "WEB_SEARCH" | "NOTEBOOK_EDIT" | "SKILL" | "SLASH_COMMAND" | "MCP_EXECUTE" <tool_target> ::= <string> | <identifier> | <file_path> | <expression> <optional_tool_param_clause> ::= <tool_param_clause> | ε <tool_param_clause> ::= "WITH" <tool_param_list> | "USING" <tool_param_list> <tool_param_list> ::= <tool_param_pair> ("," <tool_param_pair>)* <tool_param_pair> ::= <tool_param_name> ":" <tool_param_value> | <tool_param_name> "=" <tool_param_value> | <tool_param_name> <tool_param_name> ::= <identifier> <tool_param_value> ::= <string> | <number> | <boolean> | <identifier> | <array_literal> | <object_literal> <optional_tool_result_clause> ::= <tool_result_clause> | ε <tool_result_clause> ::= "->" <tool_result_binding> | "INTO" <tool_result_binding> | "AS" <tool_result_binding> <tool_result_binding> ::= <identifier>
Flowchart Rulesε
Grammar for visual flow definitions in various formats.
BNF Grammar# Flowchart <flowchart_declaration> ::= "FLOWCHART" <flowchart_name> <optional_flowchart_state> <optional_flowchart_layout> ":" <flowchart_body> <optional_flowchart_layout> ::= "LAYOUT" <flowchart_layout> | ε <flowchart_body> ::= <flowchart_line>+ <optional_error_handler> <optional_error_handler> ::= <error_handler> | ε <error_handler> ::= "ON" "ERROR" ":" <directive>+ <flowchart_line> ::= <flowchart_node> | <flowchart_edge> | <flowchart_branch> | <flowchart_merge> | <flowchart_loop> <flowchart_node> ::= <node_label> <node_shape> <optional_shape_type> <optional_node_content> <node_label> ::= <identifier> | <string> <node_shape> ::= "[" <text> "]" | "(" <text> ")" | "{" <text> "}" | "<" <text> ">" | "((" <text> "))" | "[[" <text> "]]" <optional_shape_type> ::= ":" <flowchart_shape_types> | ε <optional_node_content> ::= <node_content> | ε <node_content> ::= ":" <node_block> <node_block> ::= <directive>+ | "EVALUATE" <condition> | "EXECUTE" <function_call> | "TRY" ":" <directive>+ "CATCH" ":" <directive>+ <optional_flowchart_state> ::= "WITH" "STATE" <state_declaration>+ | ε <state_declaration> ::= <variable_name> ":" <type_annotation> "=" <expression> <flowchart_edge> ::= <edge_source> <edge_arrow> <edge_target> <optional_edge_label> <edge_source> ::= <identifier> <edge_target> ::= <identifier> <edge_arrow> ::= "→" | "↓" | "↑" | "←" | "↔" | "-->" | "--->" | "==>" | "-.->>" | "|" <optional_edge_label> ::= ":" <string> | ε <flowchart_branch> ::= <branch_source> "/" <branch_option>+ <branch_source> ::= <identifier> <branch_option> ::= <branch_condition> "→" <branch_target> <branch_condition> ::= <condition> | <string> <branch_target> ::= <identifier> <flowchart_merge> ::= <merge_source>+ "◄" <merge_target> <merge_source> ::= <identifier> <merge_target> ::= <identifier> <flowchart_loop> ::= "LOOP" <loop_source> "→" <loop_target> <optional_loop_limit> <loop_source> ::= <identifier> <loop_target> ::= <identifier> <optional_loop_limit> ::= "MAX" <number> | ε <flowchart_shape_types> ::= "process" | "decision" | "start_end" | "input_output" | "subprocess" | "database" <flowchart_layout> ::= "vertical" | "horizontal" | "lr" | "rl" | "tb" | "bt" <flowchart_name> ::= <variable_name> # ASCII Flowchart <ascii_flowchart_block> ::= <ascii_flowchart_line>+ <ascii_flowchart_line> ::= <ascii_node_line> | <ascii_connector_line> | <ascii_branch_line> | <ascii_merge_line> <ascii_node_line> ::= <indent> <ascii_node> <ascii_node> ::= "[" <text> "]" | "(" <text> ")" | "{" <text> "}" | "<" <text> ">" <ascii_connector_line> ::= <indent> "|" | <indent> "│" | <indent> "▼" | <indent> "▲" | <indent> "►" | <indent> "◄" <ascii_branch_line> ::= <indent> "/" <indent> "\" | <indent> "▼" <indent> "▼" <ascii_merge_line> ::= <indent> "\" <indent> "/" | <indent> "◄" "─" "┘" <indent> ::= <whitespace>* # Mermaid Flowchart <mermaid_declaration> ::= "MERMAID" <mermaid_type> ":" <mermaid_body> <mermaid_type> ::= "flowchart" | "graph" | "sequence" | "class" | "state" | "er" <mermaid_body> ::= <mermaid_line>+ <mermaid_line> ::= <mermaid_node_def> | <mermaid_connection> | <mermaid_subgraph> | <mermaid_style> <mermaid_node_def> ::= <node_id> <mermaid_node_shape> <optional_node_text> <node_id> ::= <identifier> <mermaid_node_shape> ::= "[" <text> "]" | "(" <text> ")" | "{" <text> "}" | "((" <text> "))" | "[[" <text> "]]" | "[/" <text> "/]" | "[\" <text> "\]" <optional_node_text> ::= <text> | ε <mermaid_connection> ::= <node_id> <mermaid_arrow> <node_id> <optional_connection_text> <mermaid_arrow> ::= "-->" | "--->" | "==>" | "-.->" | "--" <optional_connection_text> ::= "|" <text> "|" | ε <mermaid_subgraph> ::= "subgraph" <subgraph_title> <mermaid_line>+ "end" <subgraph_title> ::= <string> <mermaid_style> ::= "style" <node_id> <style_properties> <style_properties> ::= <style_property> ("," <style_property>)* <style_property> ::= <identifier> ":" <string>